As the power of tractors and agricultural efficiency has increased, agricultural implements, such as planters have increased in span, or width, to accommodate larger numbers of individual row units. Large planters generally include a main frame having a forward hitch assembly for drawing by a tractor and left and right wing sections pivotally attached to a portion of the main frame. The pivoting wing connections allow the wings to fold relative to the main frame for transport and storage of the planter. Early planters pivotally displaced the wings vertically to reduce planter width and to provide clearance for transport through narrow spaces. However, as the size of planters has increased, planter wings are generally folded in a forward direction to accommodate longer planter wings or wing sections. This evolution has necessitated the incorporation of telescoping hitch assemblies and specific folding functions to accommodate planter wings of increased length. Examples of such forward folding planter frames are shown and described in Bachman, U.S. Patent Pub. No. 2014/0000919 and Kinzenbaw, U.S. Patent Pub. No. 2013/0233580, the contents of both of which are hereby incorporated by reference in their entireties.
According to current designs, a central frame is supported by wheels. Wings that are used to support agricultural equipment are pivotally connected to the central frame. Each of the wings is adjustable between a work position where it extends laterally from the central frame and a transport position wherein it is folded forward. A telescoping hitch extends forward from the central frame and is used to connect the implement to a towing vehicle, such as a tractor. Draft links connect the front (or inner) portion of the telescoping hitch with the wings. These draft links are pinned directly to the inner hitch on opposite sides of the hitch. According to one feature of these implements, a means is provided to apply a downward force between the center frame and wings in order to adjust the weight distribution on the wings. When the wings are pivoted downward relative to the central frame in the extended working position, they tend to pull the draft links, and therefore the front portion of the telescoping hitch, rearward towards the central frame; and when the wings are pivoted upward, they tend to push the front portion of the telescoping hitch forward towards the towing vehicle. This upward and downward pivoting of the wings can occur either because of applying weight distribution forces on the wings, or as a result of natural flexing of the wings as they move across uneven ground. When the wings flex in opposite directions, they work against each other, this can cause excess stress and ultimately permanent strain in the components.
Therefore, there is a need for an improved forward folding implement frame. The current invention relates to an improvement of a forward-folding implement frame that allows for a degree of movement between the draft links and the hitch without excess stress load on the frame such as might cause flexing and strain in the frame.